I would see you dr. I have had it 4 times and it always starts with soreness in my breast and very quickly becomes very tender and hard, with the aches and headaches followed by the fever (in a matter of hours). I can sometimes get it under control in 24 hrs by being sure to empty the breast. But my breast is always sore throughout.

But maybe that's just me. If your breast is sore, I'd be seeing a dr to get antibiotics if it is mastitis. It can leave you feeling pretty bad and worsen quickly.